Vibration translating device



April 1944- G. R. YENZER 2,347,347

VIBRATION TRANSLATING DEVICE Filed Aug. 26, 1942 INVENTOR G. R. YENZER ATTORNEY Patented Apr. 25, 19?;

UNITED STATES PATENT OFFICE' VIBRATION TRANSLATING DEVICE George R. Yenzer, Queens Village, N. Y., assignor to Bell Telephone Laboratories, Incorporated, New York, N. Y., a corporation of New York Application August 26, 1942, Serial No. 456,224

, Claims. (01. 179-10041) This invention relates to vibration translating devices and the object of the invention is an improved translating device of the type in which the moving element is adapted to vibrate ina plurality of modes. I

According to the general features of. the invention thedevice has a single vibratoryelement such as a coil mounted between pole-pieces ,for vibration either torsionally or along its axis and a permanent magnet movable to either oftwo positions with respect to the pole-pieces to set up a flux which is either radial or transverse with respect to the coil. This structure is particularly useful as a phonograph'reproducer' (or recorder) since with a stylus connected to the-coil the device will reproduce .(or record) either hill and dale or lateral type records merely by moving the magnet to the proper position and without any change in the electrical circuit. a I a The invention will be more clearly understood from the following detail description andthe accompanying drawing in which:

Fig. 1 is a perspective view of a reproducer according to the invention; 7

Figs. 2 and 3 are side views showing the magnet in its two positions; and

Fig. 4 is a front .view showing particularly the pole-piece construction.

In the drawing, the signal coil Patent 2,027,169 to Harrison except that in this case the coil is supported entirely bya'single flat spring member l2 secured to the bottom piece l3 of the casing H. 'The member IZtapers toward ll and its supporting structure is of the general type shown inarm 24 of which engages the magnet when the latter is in its upper position as shown in Figs. 1 and 2. This pole-piece also extends backwardly to an L-shaped portion against which the magnet rests in its lower position as shown more clearly in Fig. 3.

With the magnet in its upper position the flux path extends from the north pole of the magnet through the Ushaped portion of the pole-piece l9, one side of the air-gap, the central pole-piece 20, the other side of the air-gap to the pole-piece l8 and the south pole of the magnet. This flux is transverse with respect to the coil I l and under this condition the device will reproduce (or record) lateral cut records.

When the magnet is moved downwardly to the position of Fig. 3, the north pole is transferred vides flowing radially across both sides of the gap iii the coil support l5 both of which may be of any suitable light weight non-magnetic metal or this vibrating structure including the stifiening fin It may be molded in a single piece from suitable thermoplastic or thermosetting material. In any case the stylus I1 is preferably of the permanent type cemented into a socket in the support l5.

As in the case of the vibratory structure shown in the Harrison'patent the spring member I2 is free to vibrate vertically when used with hill-anddale records and torsionally when used with lateral cut records.

The coil is mounted in an annular air-gap de fined by the lateral pole-pieces l8 and I9 and the central pole-piece 20, the latter being held in position by the non-magnetic member M. The pole-piece l8 extends backwardly and terminates in an L-shaped piece 22 which engages the permanent magnet 23 as shown in Fig. 1. The polepiece I9 is U-shaped at its front end the upper to pole-pieces l8 and I9 and back to the south pole by way of the arms 22 and 25. With this radial flux the device will record or reproduce hilland-dale or vertical cut records.

For convenience the magnet is fitted with a handle 26 or some -equivalent means extending through the casing so that the device may be readily conditioned for operation in either mode. While the magnet by its own attraction will remain in either position under ordinary conditions the handle 26 may be provided with a spring catch 21 and any other known form of detent or locking device for maintaining the magnet in the position in which it is set. It will also be understood that in practice suitable means would be provided for guiding the magnet in its motion from one position to the other. These guides can be of any suitable nonmagnetic material secured to the pole-pieces or secured to or formed integrally with the top or bottom plate of the casing. The leads (not shown) from the coil It may be connected to pins 28, 2B in the casing and these pins may serve both as the electrical connectors to the external circuit and the mechanical means for attaching the device to a suitable arm.

While the invention has been described with particular reference to a phonograph reproducer or recorder it will be understood that it is equally applicable to any electromagnetic device in which it is desired to produce either a radial or a transverse flux and that various modifications of the structure illustrated may be made within the scope of the following claims. 7

What is claimed is:

1. In a vibration translating device the combination with a signal coil and pole-pieces defining a gap for the coil, ota permanent magnet adapted to be moved between the pole-pieces to set up either a radial or a transverse flux in the gap.

2. In a vibration translating device the combination with a pair of lateral pole-pieces and a central pole-piece defining an air-gap and a signal coil mounted for vibration in the gap, of a permanent magnet and extension members on the pole-pieces for selectively contacting the magnet to reverse the direction of the flux between the central and one of the lateral pole-pieces.

ing an air-gap, a signal coil mounted for vibration in the gap and means for setting up a transverse or a radial flux in the gap comprising a movable permanent magnet having one pole adapted to be moved from one of the lateral polepieces to the central pole-piece and another pole adapted to maintain contact with the other lat eral pole-piece and move into contact with said one lateral pole-piece.

5. A selectively universal phonograph reproducer comprising a pair of lateral pole-pieces and 'a central pole-piece definingan air-gap, a stylus.

a signal coil attached thereto, .a vertically and torsionally resilient spring member supporting the coil for vibration in the gap and means for producing either a radial or a transverse flux in the 

